After twenty-five years of simultaneous political and economic transitions, there have been produced different outcomes in different countries. Some nations advanced well on the road of transition as Poland, while some cases produced disturbing transition outcomes in both economic and political terms, as Russia. Despite the increasing number of studies looking into causes and effects of the institutional change, none has yet explored the link between FDI flows and changes in corruption perception in transition economies. Our study is the first that investigates the impact of the size of FDI flows and its origins on the institutional development in transition and post-transition countries. The empirical results using a dataset on FDI flows among the posttransition countries during 1990-2015 suggest that they may be institutional development effects of FDI flows. The institutional convergence between developed and transition countries is, however, a long process and the preliminary results show that it does not include all the institutions.